Ribbed cover plate for coating application cylinder



F. BALL Sept. 14, 1965 RIBBED COVER PLATE FOR COATING APPLICATION CYLINDER Filed Dec. 29. 1961 INVENTOR. pzigw/ ATTORNEYS United States Patent 3,206,353 RIBBED COVER PLATE FOR COATING APPLICATION CYLINDER Fred Ball, Kingsport, Tenn., assignor to Pid Corporation, Beverly Hills, Califi, a corporation of California Filed Dec. 29, 1961, Ser. No. 163,317 6 Claims. (Cl. 161-123) This invention relates to the application of a coating material to a surface, such as a sheet of paper and more particularly to a coating plate for attachment to the coating roll of a roller coating apparatus.

Heretofore various types of coating apparatus have been proposed and utilized and in certain types of such apparatus a coating roll is provided to which is applied the coating material and thereafter, the material is applied to a surface, such as a sheet of paper, by contact between the coating roll and the surface. This type of apparatus is perfectly satisfactory for normal coating operations in which coating material, such as adhesives, ink and the like, are utilized and also where it is not necessary to maintain a highly accurate thickness of the coating material on the surface. Furthermore, these prior art coating machines have not provided an apparatus capable of applying a coating material to a surface in which accurate coating thickness is maintained and also in which the coating material is applied in such a manner that the same may thereafter be embossed with a design without causing flow of the coating material beyond the edges of the area to which the same is applied.

The coating plate of the present invention is intended to be utilized as a part of the coating roll of a roller coating apparatus in which it is proposed to apply a coating of molten plastic to the surface of a sheet of paper and to thereafter smooth coat or to emboss with a design of any desired accurate configuration without causing, flow beyond the edges as abovementioned. For some purposes, a particular coating material having a particular index of refraction is required and furthermore, such material must be relatively flexible when set and likewise, the material must be applied in a molten condition and in a layer of very accurate thickness, such conditions precluding use of presently known coating apparatus.

. It is accordingly an object of the invention to provide a coating plate for applying molten plastic to a surface, such plate being flexible to permit the same to be secured in place on a coating roll of -a coating apparatus. A further object of the invention is the provision of a coating plate for applying molten plastic to a surface, such plate being so formed as to apply the plastic in a uniform manner and with .a uniform accurate thickness. A still further object of the invention is the provision of -a coating plate for applying molten plastic to a surface, such plate incorporating spaced parallel ribs providing spaces therebetween for receiving the molten plastic, the depth of ribs determining the depth of the plastic coating and such ribs providing grooves in the coating into which the plastic may flow during a subsequent embossing operation.

Another object of the invention is the provision of a coating plate for applying molten plastic to a surface, such plate incorporating spaced parallel ribs to provide spaces therebetween for receiving the molten plastic, the ribs being inclined at a critical angle, such that the molten plastic will not flow longitudinally of the ribs and the inclination also permitting the use of a doctor blade in contact with the ribbed surface of the plate to maintain the thickness of plastic thereon in accordance with the depth of the ribs.

Further objects and advantages of the invention will 3,Z%,353 Patented Sept. 14, 1965 be apparent from the fol-lowing description taken in conjunction with the accompanying drawing wherein:

FIG. 1 is a plan view of a coating plate constructed in accordance with this invention;

FIG. 2 is fragmentary transverse sectional view of the plate shown in FIG. 1;

FIG. 3 a fragmentary plan view to an enlarged scale and showing the disposition of the ribs and the inclination thereof; and

FIG. 4 a fragmentary longtiudinal sectional view showing the relationship of the ribs to the main body of the plate.

With continued reference to the drawing, there is shown a coating plate constructed in accordance with this in vention and which may well comprise a generally rectangular flexible metal plate of suitable material and having a total thickness of approximately .036 inch. A plurality of spaced parallel ribs 10 are provided on the plate 11 and the ribs may be formed on the surface thereof by any suitable operation, such a etching the material from between the ribs 10 to provide spaces 12,

' the purpose of which will be presently described. As

indicated in .FIG. 2 of the drawing, the depth of the spaces 12 or conversely the height of the ribs '10 is approximately .025 inch and this depth is critical, in that the same determines the thickness of the plastic coating applied to the surface, as more fully set forth below. Also as shown in FIG. 2, the distance between adjacent ribs 10 is approximately one-quarter of an inch.

As shown in FIG. 1, the ribs 10 terminate inwardly of the opposite end edges of the plate 11 to provide end mar-gins 13 and 14 and also such ribs 10 terminate inwardly of the side edges of the plate 11 in order to provide side margins 15 and 16. The margins 15 and 16 provide space for engagement with suitable fastening means for securing or attaching the plate to the coating roll of a roller coating apparatus. It will be noted from an inspection of FIG. 1, that the ribs 1i occupy the entire space between the margins on the end and side edges of the plate 11.

The coating plate of this invention is attached to the coating roll of the roller coating apparatus and in order to confine the molten plastic applied to the plate 11 during the coating operation to the spaces 12 between the ribs 10, a doc-tor blade is utilized having .a blade edge contacting the crests 17 of the rib 10 and obviously, if a uniform quantity of plastic is to be received in the spaces 12 between the ribs 10, the blade edge of the doctor blade can only contact the crests 17 of the ribs 10 and cannot be permitted to move into the spaces 12 which would result in removing .a portion of the plastic therefrom. In order to accomplish this result, the ribs 10 are incline-d at an angle with respect to the longitudinal axis and this inclination is such that the edge of the doctor blade will always be in contact with the crests 17 of two or more ribs 10, thereby preventing movement of the edge of the doctor blade into the spaces 12 between the ribs 10. However, since molten plastic is being utilized and since the roll to which the plate '11 is attached is horizontal, the inclination of the ribs -10 with respect to the longitudinal axis of a plate or roll must be such that there will not be undue flow of the moltenplastic material lengthwise of the spaces 12 and ribs 10. It has been found that the optimum inclination for the ribs 10 is four degrees with respect to the longitudinal axis of the plate or roll, as shown in FIG. 3, but with plastics having different degrees of viscosityi-t may be possible to provide ribs having an angle of inclination with respect to the longitudinal axis of the plate or roller between the limits of three and five degrees.

As used in the above paragraph and in the remaining ,pecification and appended claims, the longitudinal axis 'efers to the axis defined by an imaginary line drawn be- Ween the end margins 13 and 14 of the plate 11. Any :hange in the size of the plate will not alter this interpreation of the longitudinal axis inasmuch as the ribs vill consistently extend from end margin 13 to opposite :nd margin 14.

In operation, molten plastic is supplied to the surface )f the coating plate and serves to fill the spaces 12 beween the ribs 10 and the doctor blade in engagement vith the crests 17 of the ribs 10 serves to maintain the llastic at a uniform depth in the spaces 12, such depth eing equal to the depth of the ribs 10. Also in view )f the critical inclination of the ribs 10, the molten plastic will not flow longitudinally of the plate or roll in the tpaces 12 and consequently, a uniform quantity of plastic vill at all times be present in the spaces 12. The paper )r other material to be coated is fed to the coating ap )aratus and moves in rolling contact with the crests 17 )f the plate 11, which crests as clearly shown in FIGURE 2 are relatively sharp, and during this rolling contact, the )lastic in the spaces 12 is transferred from the coating plate 11 to the surface of the paper, this coating being of in accurate uniform thickness as determined by the depth )fthe spaces 12 and furthermore, since the crests 17 of :he ribs 10 contact the surface of the paper, longitudinal grooves Will be provided in the plastic coating and such grooves provide spaces into which the plastic may flow during a subsequent embossing operation, thereby preventing fiow of the plastic outwardly of the area desired. lhe coating plate of this invention may be utilized in a iigh speed coating operation in which molten plastic is :ontinuously supplied to the ribbed surface of the coating plate and sheets of paper or other materials to be coated are continuously fed in rolling contact therewith, thereby providing a high speed coating operation commensurate with high speed printing processes.

While the coating plate of this invention may appear relatively simple in construction, nevertheless, the same has solved a particularly vexing problem in the field of accurately coating sheets of paper or other material with 1 plastic to be subsequently embossed in the form of a design without causing flow of the coating beyond the edges and it has been found that the coating plate of this invention provides the desired accurate coating in a mannet to permit the subsequent desired embossing operation.

By way of further background, early work on the coating plate showed that this would be diflicult to design. Wells having round, diamond or square shape provided a land that imparted a pattern of melt to the paper that could not be removed. After much trial and error it was found that transverse land patterns could be removed by embossing whereas lands about perpendicular to the traverse could not be removed. As indicated above, while a four degree angle to the traverse is preferred, an angle up to 20 may be quite serviceable as long as the lands travel transversely.

It will be obviousto those skilled in the art that various changes may be made in the invention without departing from the spirit and scope thereof and therefore the invention is not limited by that which is shown in the drawing and described in the specification, but only as indicated in the appended claims.

What is claimed is:

1. A coating plate for attachment to the coating roll of a roller coating apparatus, said plate comprising a generally rectangular flexible metal plate having a longitudinal axis, a plurality of spaced parallel ribs on the surface of said plate, said ribs extending longitudinally and terminating inwardly of the opposite end edges of said plate, rib free margins on opposite side edges of said plate, said ribs occupying the entire surface of said plate between said margins, said margins serving to engage fastening means for attaching said plate to said roll with said plate longitudinal axis extending generally parallel to the axis of said roll and with said ribs being inclined at an angle of between three and five degrees with respect to the longitudinal axis of said plate, the spaces between said ribs serving to receive molten plastic for coating :1 surface in rolling contact with said ribs and the depth of said ribs serving to determine the thickness of the plastic coating applied to said last named surface.

2. A coating plate as defined in claim 1, in which the angle of inclination of said ribs is four degrees.

3. A coating plate as defined in claim 1, in which the crests of said ribs are relatively sharp.

4. A coating plate for attachment to the coating roll of a roller coating apparatus, said plate comprising a generally rectangular flexible plate, a plurality of spaced parallel ribs on one surface of saidplate and said ribs being inclined at an angle of four degrees with respect to the longitudinal axis of said plate, the spaces between said ribs serving to receive molten plastic for coating a surface in rolling contact with said ribs and the depth of said ribs serving to determine the thickness of the plastic coating applied to said last named surface, said plate being adapted to be attached to said coating roll with said platelongitudinal axis extending generally parallel to the axis of said coating roll.

5. A coating plate for attachment to the coating roll of a roller coating apparatus, said plate comprising a generally rectangular flexible plate, a plurality of spaced parallel ribs on one surface of said plate and said ribs being inclined at an angle up to 20 with respect to the longitudinal axis of said plate, the spaces between said ribs serving to receive molten plastic for coating a surface in rolling contact with said ribs and the depth of said ribs serving to determine the thickness of the plastic coating applied to said last named surface, said plate being adapted to be attached to said coating roll with said plate longitudinal axis extending generally parallel to the axis of said coating roll.

6. A coating plate for attachment to the coating roll of a roller coating apparatus, said coating plate comprising:

a normallyplanar generally rectangular plate fabri cated of a flexible metal which can be readily manually formed to conform the plate to the configuration of the coating roll;

said coating roll having a central axis and said rectangular plate having a longitudinal central axis with said central axes being substantially parallel to one another when said plate is wrapped around said roll;

said plate being peripherally bounded by opposed end edges and opposed side edges;

a plurality of spaced parallel ribs on one planar surface of said plate;

said ribs extending continuously longitudinally between said end edges and terminating inwardly thereof to define rib-free end margins;

the outermost of said ribs being spaced inwardly from said side edges to define rib-free side margins;

said side margins serving to engage fastening means for attaching said plate to said coating roll with said ribs being angularly disposed to the longitudinal central axis of said roll;

said angle of disposition of said ribs being substantially three to five degrees;

said ribs defining between them, a series of substantially equally dimensioned spaces which are adapted to receive molten plastic to be coated upon a surface which passes in rolling contact across said coating plate when the same is mounted upon said coating roll;

said ribs being of equal height, with the height of said ribs serving to determine the thickness of the plastic coating applied to said surface.

(References on. following page) 5 6 References Cited by the Examiner 2,199,228 4/40 Obenshain et a1. 117111 2,564,492 8/51 Moffat et a1 118-243 X UNITED STATES PATENTS 2,714,365 8/ 5 5 Rowlands.

g: 2 101 157 3,006,317 10/61 Showalter 118-212 5 10/23 Osgood FOREIGN PATENTS 12/25 Dixon 117111 X 9,511 1914 Great Britain.

9/34 Fowler. 5/3 Shepherd 11 212 RICHARD D. NEVIUS, Przmary Exammer. 8/ 39 Hayes. 1 JOSEPH B. SPENCER, Examiner. 

1. A COATING PLATE FOR ATTACHMENT TO THE COATING ROLL OF A ROLLER COATING APPARATUS, SAID PLATE COMPRISING A GENERALLY RECTANGULAR FLEXIBLE METAL PLATE HAVING A LONGITUDINAL AXIS, A PLURALITY OF SPACED PARALLEL RIBS ON THE SURFACE OF SAID PLATE, SAID RIBS EXTENDING LONGITUDINALLY AND TEMINATING INWARDLY OF THE OPPOSITE END EDGES OF SAID PLATE, RIB FREE MARGINS ON OPPOSITE SIDE EDGES OF SAID PLATE, SAID RIBS OCCUPYING THE ENTIRE SURFACE OF SAID PLATE BETWEEN SAID MARGINS, SAID MARGINS SERVING TO ENGAGE FASTENING MEANS FOR ATTACHING SAID PLATE TO SAID ROLL WITH SAID PLATE LONGITUDINAL AXIS EXTENDING GENERALLY PARALLEL TO THE AXIS OF SAID ROLL AND WITH SAID RIBS INCLINED AT AN ANGLE OF BETWEEN THREE AND FIVE DEGREES WITH RESPECT TO THE LONGITUDINAL AXIS OF SAID PLATE, THE SPACES BETWEEN SAID RIBS SERVING TO RECEIVE MOLTEN PLASTIC FOR COATING A 